Know the basic rules of good nutrition
Eating healthfully should be a life-long goal for all of us not just for kids. You probably know the basic rules of good nutrition already: eat whole grains, fruits, vegetables, lean meats, poultry and fish; avoid foods that are high in fat and sugar. If you stick to that plan as much as possible, you'll be well on your way towards eating healthfully.

Teach kids at the supermarket
One good place to teach kids how to eat healthfully is at the supermarket. Involve them in the process of grocery shopping. Teach them to read labels. Show them what portion sizes look like. Stock up on healthy snacks like fruit, yogurt, pretzels, etc. Have them pick out a new fruit or vegetable each time you shop. Avoid buying cookies and chips -- after all, your kids can't eat snacks that aren't in the house.

Involve your kids in food preparation
Kids are more likely to eat what they've cooked. Plus, you'll all have fun together. Show them how to steam vegetables and roast meats. Explain to them why you cook with olive oil or canola oil instead of butter. Have them look up some fun new recipes online and choose one to prepare with you. (As an added benefit, you may come home one day when the kids are older and discover they've made a meal for you!)

Have dinner together as often as possible
At the dinner table, take a seat and relax. Although many families are overscheduled, taking the time to have dinner together as often as possible leads to healthier eating habits and stronger family bonds. Serve small-ish portions and encourage kids to eat slowly, savor their food and give their stomachs a chance to feel full.

Make your eating changes gradually
Practice what you preach in terms of nutrition. You can't expect kids to eat steamed broccoli and extra lean burgers if you're having fried chicken and French fries for dinner.

Remember that it's best to make your eating changes gradually. You'll encounter much less resistance along the way. For example, don't try to switch from whole milk directly to skim but take some intermediate steps that include 2% and 1%. And if you only make it as far as 2%, don't fret. Even small changes add up over time.